Firearm with exchangeable barrel



l Patented Sept. 10, 1.935

UN1T1=1D STATES 2,014,184 l FIREARM WITH EXCHANGEABLE BARREL Friedrich Linder, Dusseldorf, Germany, assignor to Rheinische Metallwaaren-und Maschinenfabrik, Dusseldorf, Germany, a-corporation of Germany 'Application November 27, 1933, serial No. 699,98 In Germany April 10, 1933 c 3 claims., The invention relates to rearms of the'ex'- changeable barrel type. object of the invention is to provide a safety device which automati cally makes it impossible for a shot to be disfucharged if the barrel is incorrectly mounted in the weapon, thereby avoiding the result of a faulty mounting, which, on a shot being red, would interruptA the functioning of the weapon and cause serious damage. In such cases, which are particularly liable to occur when the barrel of a machine gun is changed while it is in actual use or during assembly of large calibre machine guns which have been taken to pieces for pur'-4 poses of transport, the safety member accordingV to the the invention co-operates with a housing'.A

. to jam the barrel and breech casing in a' position preventing opening of the breech, which rendersv it impossible for the gun to be loaded. The .gun crews attention is thusimperatively directed to the fact that the barrel has been incorrectly inserted, and before the gun can be fired at all,the

gun crew must bring the barrel into a satisfactory state of coupling.

The drawing illustrates a typical embodiment of the Ainvention and shows by way of example a large calibre automatic gun having a sliding barrel, bolted breech, andfa bayonet joint type of barrel connection; in a particularly advanta-A geous formof construction the locking member which secures the bayonet connection against detachment at'thesame time forms the new automatic safety device. p p V Fig. 1 shows a longitudinal section of the mid,-v dle part, with the barrel connection of the gun, and f y Figs. 2 and 3 show cross-sections at the plane of the safety deviceand the -bayonet connection on the lines 1 1, 11--11 of Fig.` 1 respectively.l

The barrel a of the gun is adapted' to be re*- `moved, vin known manner, from theV housing of the gun, either by moving it forwardly,` or backwardly together with the breech casing b and the breech-- block d whichxis bolted thereto.

The breech bolting, which is not shown in the drawing, is of theV type usually found in such guns, vwherein the breech for ejecting a' red cartridge and for loading doesnot openA until a definite distance of recoil has been traversed, which distance it covers together with the breech A casing b and the barrel ain closed and bolted position. j v

For its connectionfthe barrel is provided on the y vrear end with three coaxial series of bayonet lugsai distributed-over'its periphery, which lugs when the barrel has been properly inserted, en-

gage behind corresponding lugs b1 on the breech casing b,` which surrounds the barrel. over a considerable length near the breech and closes it. To the right (Fig. 1) the bayonet lugs a1, which are for instance of the same thickness throughout, there is .provided a thickerI projection a' which engages in a correspondingly wide recessb in the breech casing. The designv of the projections and grooves is such as to prevent thebarrel after it has vbeen inserted axially in the l0 -breech casing b, from turning into bolting posi- 'tion unless it has been inserted to the required Y depth at which it abuts the'shoulder bz. In this position, and after it is turned, all the lugs a1 interlock with the lugs b1 andtherefore, when sub- 15 jected to 'ring stress, the coupling possesses the, requisite strength and rmness.

In the coupling. position shown in the draw.-A ing, the projection e2 of' a: locking mem r e mounted in the breech casing so as to be c pable 20 of bending upwardly, engages in a safety notch a2 in the barrel, in order thatthe latter cannot be turned accidentally out of theposition attained by it. v

When the locking member e is sunk in the 25 outerV wall of the breech casing b, the latter with the barrel and the breech block can be displaced in the housing-c, towards the right (Fig. 1). Barrel a, breech casing` b and breech d can Athen, be withdrawn in the usual 'manner for loading the 30 gun and after a certain length of recoil the f breech mechanism, not shown and of the kind usual in guns of this type, unlocks the breech d so that vit can be opened and a cartridge inserted f in the cartridge seating. of the barrel a. If, how- 35 ever, the bayonet coupling has not been properly engaged, theprojection e2 on the locking member will rest on a reduced portion aiof acollar- .a4 of the barrel, causing the shaft e1 of the lockj ing-member to bend flexibly outwards. Thereby 40 the part thereof which protrudes forwardly from the housing c tends to jam in a recess c1 inthe housing, with the result that the breech casing cannot be moved tothe right to open the breech,

and the g'un cannot be'loaded and also cannot be 45'v fired because the breech mechanism frees the l breech d after the barrel a and breech d have together travelledback a certain distance.

The locking member e is flexibly gripped in the rear portion of the breech casing grooveba which is of dovetcailed form from the point b4 towardsv the breech, and is secured against longitudinal displacement by the engagement of its lower projection e3 in an opening in the base of the groove.\ The shoulders as, aa at the ends of the reduced 55 portion a3 of the c llar a4 of the barrel, in cooperationwith the locking member e, limit the turning of the barrel both in the non-assembled position and when the bayonet connection has been completely made. In order to remove the `barrel from the breech casing the front .part of the locking member is raised by hand and disengaged from the barrel notch a2. On the insertion of the barrel into the breech casing, owingl to the oblique under surface of its front end, the locking member is guided automatically over the projecting barrel members. v

I claim: i

1. In a firearm, a housing, a breech casing slid^ able in the housing, a barrel, a bayonety connection between the barrel ,and the casing permitting removal of the barrel therefrom, and exible locking means having projections engaging re- 'cesses in the barrel and breech casing, said rreans being slidable along with the barrel and breech casing in the housingwhen the `barrel is properly mounted and in 'case of improper mounting said means being bentby incomplete engagement of one of its projections in the corresponding recess into a position causing jamming of the barrel and breech casing in the housing in a position I preventing opening of the breech, and said bayonet connection between the barrel and breech casing comprising a plurality of interrupted coly lars and separating grooves on each part,V the dimensions of said collars and grooves being such that the barrel can be turned to lock the connecrtionv only when all the collars and grooves are in correct registering relationship.

2. In a firearm having a housing and a recoil 2,014,184 l l i system mounted therein comprising a barrel, a, breech casing to vwhichthe barrel is removably connected, and a breech blo'ck which remains closed during the first portion ofthe recoil; the

arrangement of connections between thebarrel 5"- and the breech casing engaging each other over a A fixed axial length, a` locking member engaging said barrel and breech casing and slidable freely therewith in the housing when the barrel and breech casing are interconnected over said xed 10 axial 1ength,'.and means Veffective upon said locking member only when the barrel is connected `with-the breech casing over an axial length other than the said xed length to cause said locking member toarrest the recoil system in said first 15 portion ofthe recoil.

3. In a firearm having a housing and a recoil system mounted therein comprising a breech casing, connections for removably mounting the barrel in the breech casing, said connections being 20 .fully engaged by predetermined rotary and axial movements of the barrel and casing relatively to f each other,A and a breech block which remains V"closed during the first portion of the recoil; the

f FRIEDRICH LINDER. 3 5 

